In tandem with one of the most significant residential developments in years, the City of Cranbrook is installing the latest infrastructure technology to handle the stormwater run-off in the neighbourhood of Innes Avenue.
A new stormceptor system, as it’s known, is being installed on Innes Avenue, adjacent to the new Rockyview Place development, that will handle all the storm run-off in the area, with outfall into Elizabeth Lake. The new system, which is being installed Monday, will separate and filter all impurities and contaminants out of the storm water, and moderate the water’s flow into the lake, resulting in minimal impact on the sensitive wetland and wildlife sanctuary.
“The water that flows into that area right now does get into the lake eventually — it just does it over land,” said Mike Matejka, Manager of the Infrastructure Planning & Delivery Division at the City of Cranbrook.
“Everything along the road flows through some of the adjacent properties, and areas that have horses, and livestock … So it wasn’t necessarily an ideal situation to begin with, which is why the City decided to do some additional investment, and work with the developer of the property to improve those things at the same time.”
The stormceptor is a hydrodynamic separator that removes pollutants and materials from stormwater and snowmelt runoff. The system is designed to protect waterways from hazardous material spills and stormwater pollution, including sediment, oils, and pollutants that attach to particles.
“Most contaminants that would come into the storm system from any overland flow or rainfall would usually be things that float on top of the water, which are not good,” Matejka said. “That can include trash, oils or hydrocarbons or anything that would attach to those items that float on top. Those things that float on top are captured in the upper portion of the chamber.”
And any heavy contaminants that sink to the bottom of the water, such as heavy metal, sediment or rock, are filtered into another large storage chamber.
Matejka said the stormceptor is a large structure, with a large capacity, that stores a lot of material in the collection chambers. The City of Cranbrook’s hydro-vac trucks will routinely remove the material in both the upper and lower chambers, and dispose of it.
The stormceptor is going to be installed on Innes Avenue, in the roadway itself, and from there, there is a pipeline that leads to the outfall.
“There isn’t any other storm sewer connected downstream of that location — that’s why it was an ideal location to put it,” Matejka said.
This is the second stormceptor the city has installed. Flooding concerns in the area near the Public Works yard, along with a higher potential for contaminants in an industrial area, led to the installation during upgrades to Cobham Avenue in 2018. Since then, the system has proved effective.
“We’ve looked into the chambers and seen that it’s working well,” Matejka said. “It does have to slow down the water in order for this process to take place … we had some concerns as to if it would restrict the flow and cause some backup of the stormwater events. But we haven’t seen anything to date, and it does show it can appropriately handle the flow.”
The City has started a program to identify other locations in the community where the stormceptor can be installed in an existing storm system, and where it could have the most benefit. Any stormwater entering Joseph Creek that could potentially be contaminated could retrofited to improve the quality of the water from the run-off.
Rockyview Place, developed by Broadstreet Properties, is a new apartment and townhouse development along Innes Avenue. It will have four apartment buildings, 10 townhouse buildings, a playground, community gardens and rental centre.
The development will also lead to significant upgrades to Innes Avenue itself.